Method of producing sand-lime bricks



I Patented Feb. 4, 1930 HARRY WILLIAMS: enAnLToN, on NEW YORK,,1\T. Y

METHOD or rnonucme SAlqiD-LIME :BRiroKs No'Dravving.

This invention relates to a method of improving the quality ofsand lime brick, and other materials manufactured. similar Wayybyeifecting a reduction in water absorption, and an increase in the water shedding properties.

The object of this invention is to produce a brick that, When laid in the Wall, Will completely shed the Water. Thus during a rain it Will run olf instead of being soaked in and appearing in the form ofdew on the inner Wall. As an additional object I desire to so fill the V voids and interstices With a colloidal ma- .terial, that the more or less unavoidable surface'and internal Weathering Will be reduced to a minimum.

As an example of my invention I may take a mixture of about 90 parts of clean sharp I V sand, and 10 parts, (calculated by Weightas C210,) of lime, substantially free of MgO, the

' I lime being'thoroughly hydrated. I intimately mix the two and so regulate themoisture content that When the mixture is squeezed inthe palm of the hand, and the hand opened, the mass Will just hold together. The material is then moulded and compressed in the usual sand lime brick presses. These machines are Well known and do not require any further explanationexcept to state that they exert a pressure of from to 150 tons, on the mixture composing each brick, and may thus be classed as "high pressure machines, After pressing the green brick are lifted oh the press and piled edgewise, brick against 1 brick, onthe car, the ends alone being exe posed.v The cars carrying about 1000 brick, f are run into hardening cylinders and subjected to the action of steam under a-pressure 1 of from 110 to 135 pounds for, about 8 hours, 1 The above mentioned steps are well known in the sand lime brick industry, and do not vconstitute apart of this invention. At this point I vary the usual procedure. I inject into the sealed cylinders, either before or after the steam is blown off, a solution capable of-reacting With or impregnating the brick,

. and improving it. As one example Imay use a 2 to 3% solution of sodium stearate or 5. alkali salt of like fatty acid. After the brick ifnp ncanqn filed November 18, 1926. Serial my. 149, 27e.

have been immersed for from ten to: twenty minutes, the solution is drawn otflthe cylinder opened and: the cars immediately pulled out to cool and dry.

' Although I have-specified sand lime brick 55. in the reference to my new" method of treatment, I Wish toinclude all materials'ofthis nature, suclras tile, building'blocks, insulating partitions, roof tile, and: internal paving blocks. Sand: lime brick"typifies,v atype of 0.0- plasticsin whiclrtwo inorganic materials are intimately mixed and compressed, and then exposedtothe action'of'steam'under pressure, and in which the steam induces interactions.

and the mass ispermanently cemented to gethen: during and resultingfrom the chemical action. I

It is: generally conceded that the binding agent-in sand limebrick isa hydrous silicate formed by the interaction of the lime and sand during: the steaming operation. Ever-y particle of sand is-coated withlime', and) as t-he'hydrous silicate is formedfit cementsthe unacted' on portionsofthe sand grains to I gether; The object in subjecting the mass to high pressure is to bringtheparticles inas intimate a contact aspossible, that the binding agent may exert its maximum efiiciency. In spite of this there is always a decided porosity and Water absorptiondue to the unfilled voids and the-affinity of the hydrous-silicate for W-aten The almost universah criticism of'sand lime brick is itsexcessive absorption, and in some casesthe almost avidity \vi tli wh ich it ,sucksvup ater.

' I have now) discovered a method of over coming this difiicultyby employing the most suitable time to treat the brick with; a solution capable of! reacting with it: and impregnating it; I; take thebrickzimmediately after the 1 hydrous silicate is= formedtzandi before it has cooled down, anditlius the solutionvisdrawninrand replaces rthe:condensing steam: which fillS DllBVOidS-J Ais tlieibrick at the end of the steaming'operatiom arein: a sealed cylinder I usually addi'thesolution directly; This condensesthe steamandisforms apartialva'cuum inthezbody ofzthezbrick; and the aqueous J liquid is aidedfin penetrat ing, as above mentioned. The brickss are 199 ing off a portion of the steam;adding sufiitreated Without removal from the cars, and

the entire mass, including the cars, are immersed.

Another method of carrying out my invention consists in removing the hot brick from the cylinder and at once immersing them in a liquid bath. This is scarcely, as efficient because. the brickv cool 01f to a certain extent before the treatment, and do not as rapidly expel and evaporate the water after the treatment. In addition a treat ment after the brick are removed from the cylinder involves considerable additional labor, handling and equipment; a,

As above mentioned the steam may be entirely blown off after the hardening,-an'd be fore the solution is pumped in, but I- prefer to only partially blow off the steam andleave enough to heat up the incoming solution, and also cause a partial vacuum due to the condensation of the steamw; V.

Although I have referred treatmentwitlrsolutions that will reduce the water absorption, I do not Wish to be limited in any Wayin this respect. I may employ any aqueous fluid that vWill react with the brick to improve it in any manner, such as in strength, color, texture, etc. The present application deals more particularly with my discovery of the auspicious time in the process of manufacture, to efiect this treatment.

I claim 1. A method 'of manufacturing sand lime brick whichcomprises subjecting it to steam Y pressure in a hardening cylinder till the brick have attained the required strength; blowcient aqueoussolution to condense the steam remaining 1n the hardening cylinder; draw,-

7 ing ofl'the liquid and removing the brick from the cylinder to cool and dry. I

v 2. A method of manufacturing sand lime brick which comprises'steaming' it under a 1 pressure of 135 pounds fora period of 8 hours, partially blowing off the steam and retaining'sufiicient to heat. the incoming aqueous solution to slightly below the boiling point; injecting into' the hardening cylinder an aqueous solution capable of acting on the brick and improving its quality; blowing offfthe aqueous solution and withdrawing aria-1y it ih 4. A step in the process of manufacturing sand lime brick which comprises injecting into the hardening cylinders in which the brick are steamed under pressure, an aqueous solution capable of improving the quality of the brick; and discharging the solution from p the hardening cylinders.

tion capable of improving the quality; re-

moving them from the solution and allowing to dry. 7 V

' ABBY WILLIAMS CHARLTON.-

the brick from thecylinders to permit them h to cool and dry.

3. A step in the process'of manufacturing sand lime brick which comprises immersing iii-the hardening cylinder the hot brick, whose voids are filled-With steam, in a solution at a temperature sufficiently low tocondense all thestea'rn in the brick, and accelerate the absorption ofthe liquid by the brick; the said solution carrying a salt capable of uniting With the recently formed hydrous silicate and free lime to produce a gelatinous waterrepelling colloid in the interstices of the brick. 

